Stock Incentive Plans

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Our 2016 Long-Term Incentive Plan (“2016 Plan”) authorizes up to 10,000,000 shares of common stock to be issued at the discretion of the Compensation Committee of the Board of Directors. Our non-employee directors, officers and key employees are eligible to participate in the 2016 Plan. The 2016 Plan allows for the issuance of, among other things, stock options, stock appreciation rights, restricted stock, deferred stock units, performance units, and dividend equivalent rights. Vesting periods for options, deferred stock units and restricted shares generally range from three to five years. Options expire ten years from the date of grant.

Under our long-term incentive plan, certain restricted stock awards are market, performance and time-based. For market and performance based awards, we will grant a target number of restricted stock units, with the ultimate award determined by the total shareholder return and operating performance metrics, measured in each case over a measurement period of three years. These awards vest after the end of the performance periods. The expected term represents the period from the grant date to the end of the performance period. Compensation expense for these performance grants is measured based on the probability of achievement of certain performance goals and is recognized over the performance period. For the portion of the grant for which the award is determined by the operating performance metrics, the compensation cost is based on the grant date closing price and management’s estimate of corporate achievement of the financial metrics. If the estimated number of performance based restricted stock to be earned changes, an adjustment will be recorded to recognize the accumulated difference between the revised and previous estimates. For the portion of the grant determined by the total shareholder return, management used a Monte Carlo model to assess the fair value and compensation cost. Forfeitures are accounted for as they occur.

The following table summarizes compensation expense recognized for the periods presented (in thousands):


	Year Ended December 31,
	2021		2020		2019
Stock options	$	1,088	$	—	$	—
Restricted stock	16,724		28,318		25,047
Total compensation expense	$	17,812	$	28,318	$	25,047

Stock Options

During the year ended December 31, 2021, we granted 311,306 time-based stock options at a weighted average exercise price of $67.17, all of which were outstanding and non-vested at December 31, 2021. The grant date fair value of $14.64 was estimated on the date of grant using the Black-Scholes option pricing model. As of December 31, 2021, there was $3,470,000 of total unrecognized compensation expense related to unvested time-based stock options that is expected to be recognized over a weighted-average period of 3 years. Time-based stock options outstanding at December 31, 2021 have an aggregate intrinsic value of $2,763,000.

During the year ended December 31, 2021, we granted 832,356 performance-based stock options at a weighted average exercise price of $83.44, all of which were outstanding and non-vested at December 31, 2021. The grant date fair value of $20.31 was estimated on the date of grant using the Black-Scholes option pricing model. These options have a performance condition based on a Funds From Operations goal measured over the performance period of January 1, 2022 to December 31, 2024. These awards vest over two years after the end of the performance period, with a portion vesting immediately at the end of the performance period. Compensation expense is measured based on the probability of achievement of the performance goal and is recognized over both the performance period and vesting period. At December 31, 2021, the performance goal is not probable of being achieved.

Restricted Stock

The fair value of the restricted stock is equal to the market price of the Company’s common stock on the date of grant and is amortized over the vesting periods. As of December 31, 2021, there was $22,055,000 of total unrecognized compensation expense related to unvested restricted stock that is expected to be recognized over a weighted-average period of two years. The following table summarizes information about non-vested restricted stock incentive awards as of and for the year ended December 31, 2021:


	Restricted Stock
	Number of Shares (000's)	Weighted-Average Grant Date Fair Value
Non-vested at December 31, 2020	405	$	69.35
Vested	(208)	63.21
Granted	470	71.41
Forfeited or expired	(101)	79.92
Non-vested at December 31, 2021	566	$	76.28

Defined Contribution Plan

We sponsor a 401(k) plan which is available to substantially all U.S. employees. We match a percentage of employee contributions up to 5% of an employee's wages and provide a discretionary profit sharing contribution calculated as a percentage of eligible compensation. We recognized expense of $3,477,000, $3,323,000 and $2,975,000 during the years ended December 31, 2021, 2020 and 2019, respectively, related to this plan.